By this time, unsurprisingly, the cat was nowhere to be found.
She was more apparent on Sunday and Monday, loudly telling me how hungry she was before I'd even got the door unlocked (although I had to deal with the demands of the alarm first, since the cat wasn't going to up the volume and start texting her owners after twenty seconds had elapsed). The desperate meowing was clearly all an act, since she wasn't hungry enough to eat the dead mouse she left in the hallway for me.
I did a final feed yesterday, as my friends had been held up on their return journey, and left this advisory to prevent the cat wangling another meal out of them when they got back:
